London, Nov 4 (IANS): Some psychoactive drugs dubbed as "doping for lazy people" can encourage sedentary people to exercise, experts suggest.

Physical exertion, along with excuses like lack of time, are some of the main perceived barriers to exercise. This is not surprising because humans are evolved to be "lazy".

"Reducing the perception of effort during exercise using caffeine or other psychoactive drugs (methylphenidate and modafinil) could help many people stick to their fitness plans," said Samuele Marcora, director of research at University of Kent.

The perception of effort is one of the main reasons why most people choose sedentary activities for their leisure time.

Compared to watching television, even moderate-intensity physical activities like walking require considerable effort.

Similarly, a reduction in perception of effort would be very helpful to the many people who find exercise difficult as they are overweight and exercise after work in a state of mental fatigue.

"There is no opposition to the use of psychoactive drugs to help quit smoking or treat obesity, the negative perception of doping in sport may prevent the use of stimulants (a drug or substance that makes you feel more awake and active) and other psychoactive drugs to treat physical inactivity," stated Marcora.

Physical inactivity is responsible for twice as many deaths as obesity and a psycho-pharmacological treatment for physical inactivity can be considered seriously, the authors noted in a paper that appeared in the journal of Sports Medicine.